1. Field of the Invention
This invention relates to vacuum cleaners of the type employing a dirt filter and, more particularly, to a convenient and cost effective means for selectively locking a dirt filter in effective dirt collecting relation within a vacuum cleaning apparatus or rendering the dirt filter separable from the vacuum cleaner for disposal and replacement.
2. Description of the Prior Art
It is well known in the vacuum cleaner art to provide latches devoted specifically to the retention of dirt filter retaining means on the cleaner body as disclosed, for instance, in U.S. Pat. No. 1,558,006 of Fisker, Oct. 20, 1925.
U.S. Pat. No. 3,323,675 of Van Der Ham et al, June 6, 1967, discloses a cannister vacuum cleaner in which a dirt filter retaining latch is provided which can be snapped open by shifting the carrying handle of the cleaner into an extreme position.
Numerous disclosures exist in the prior art of vacuum cleaners which, in addition to locking devices devoted specifically to retention of dirt filters in the cleaner body, also provide a shiftable handle which in certain useable positions of the handle interfere with complete removal of the dirt filter from the cleaner as shown, for example, in U.S. Pat. No. 2,390,196 of Taylor, Dec. 4, 1945 or U.S. Pat. No. 3,758,914 of Nupp et al, Sept. 18, 1973. The specifically devoted dirt filter retaining latch devices of the prior art are an expense reducing the cost effectiveness of the cleaners. The disclosures of handle constructions which in certain useable positions interfere with complete dirt filter removal do not prevent partial displacement of the dirt filters and, thus, do not prevent spilling of collected dirt.